Truckee Meadows Water Authority to add fluoride to the drinking water in the Reno-Sparks area drew passionate opposition before a legislative committee Wednesday.

Opponents of Senate Bill 311 said Washoe County voters three times have rejected adding fluoride because it presents health risks to infants, cancer patients and others.

“The science is not all in support,” Laurie Yarborough, representing the Nevada Clean Water Coalition, told members of the Assembly Health and Human Services Committee.

Janine Hansen of the libertarian Nevada Eagle Forum said Washoe County voters have been clear on the issue, voting down a ballot question as recently as 2002.

Supporters of the bill, including dentists and other health-care officials, said fluoridation has been proven beneficial to dental health, citing Las Vegas as an example. Voters in Clark County approved a fluoridation ballot question in 2000.

Dr. Tyree Davis of the Nevada Dental Association and the “Miles for Smiles” dental program, said he was shocked at the poor dental health in Las Vegas when he moved there just before the measure passed in Clark County.

“I thought I had moved to a third-world country,” he said. “The dental decay among these children was simply devastating.”

He said after eight years of fluoridation, the problem has improved markedly.

Reno dentist Joel Glover said adding fluoride would result in a decrease in tooth decay and reduce health-care costs to the state. He said many families who can’t afford to take a child to the dentist take them to emergency rooms for treatment and taxpayers get hit with the cost.

The TMWA board opposed the bill and estimated the cost to start the program at about $5 million, to be borne by customers. The board voted last week to seek a ballot question before being required to start the fluoridation program.

The bill requires a fluoridation ballot question in 2010.

The bill passed in the Senate last week 10-9 along party lines, with all Democrats in favor, all Republicans opposed and two not voting.

The committee took no action Wednesday. The bill must pass in committee and on the Assembly floor before being sent to Gov. Jim Gibbons, who has said he probably would veto it.